"A Wrinkle in Time" -- which L'Engle said was rejected repeatedly before it found a publisher in 1962 -- won the American Library Association's 1963 Newbery Medal for best American children's book. Her "A Ring of Endless Light" was a Newbery Honor Book, or medal runner-up, in 1981.

In 2004, President Bush awarded her a National Humanities Medal.

Keith Call, special collections assistant at Wheaton College in Illinois, which has a collection of L'Engle's papers, said he considers her the female counterpart of science fiction author Ray Bradbury because people loved her personally as much as they loved her books.

"She was tremendously important initially as a children's book author, and then as she wrote meditative Christian essays, that sort of expanded her audience," he said. "She spoke exactly the way she wrote, very elegant, no nonsense, crisp, and deeply spiritual."

"Wrinkle" tells the story of adolescent Meg Murry, her genius little brother Charles Wallace, and their battle against evil as they search across the universe for their missing father, a scientist.

The brother and sister, helped by a young neighbor, Calvin, and some supernatural spirits, must pass through a time-travel corridor (the "wrinkle in time") and overcome the ruling powers on a planet with a totalitarian government reminiscent of George Orwell's "1984."

"A Wrinkle in Time" exposes readers to the words of great thinkers, as its characters quote Shakespeare, the Bible, Euripides, Dante and others.

Born Madeleine L'Engle Camp in 1918, L'Engle graduated from Smith College in 1941 and worked as an actress in New York City. There, she met her future husband, Hugh Franklin, an accomplished stage actor who became known later for his portrayal of Dr. Charles Tyler on the soap opera "All My Children."

They had a son, Bion, and two daughters, Josephine and Maria. The couple had adopted Maria after her parents, who were friends of theirs, died.